Logotyp: till Uppsala universitets webbplats

The Water-Energy-Food (WEF) Nexus is high-dimensional and sensitive to control inputs, such as policy changes. Constructing Nexus models to predict policy impacts is time consuming, and the temporal resolution of the available data is often coarse, limiting the use of many data-driven methods. We investigated the applicability Dynamic Mode Decomposition with control (DMDc) as a method of performing policy impact predictions. A high-resolution System Dynamics Model (SDM) of the Nexus in Latvia was used to simulate the impacts of different policies on the Nexus at annual resolution between 2000 and 2050 (m = 50 snapshots). This simulated data was used to assess how well DMDc could reconstruct policy impacts based on data alone. To obtain numerically stable DMDc models with just 50 snapshots, linear interpolation was used to artificially inflate the data to monthly resolution (m = 600). Three policies based on the SDM were tested for two different data sizes,small (n = 15 variables) and large (n = 100). With 5–15 control-policy variables specified, DMDc was able to reconstruct the impacts in both the small and large data sets for two out of the three policies with moderate accuracy (with a Nash-Sutcliffe Efficiency, NSE > 0.4). DMDc was able to capture the general trends in the data but not interannual variability. These findings suggests that DMDc shows promise for impact assessments, but policy variables have to be carefully selected. Improvements to the DMDc pipeline that could improve performance and interpretability are discussed, including data pre-processing steps, architectural changes, and modelconstraints informed by expert- or stakeholder opinion.

Droughts, traditionally less associated with high-latitude regions, are emerging as significant challenges due to changing climatic conditions. Recent severe droughts in Europe have exposed the vulnerability of northern catchments, where shifts in temperature and precipitation patterns may intensify drought impacts. This study investigates the dynamics of drought propagation in high-latitude regions, focusing on four key aspects: (1) the typical lag time for drought conditions to propagate from initial precipitation deficits to impacts on soil moisture, streamflow, and groundwater systems; (2) the probability of precipitation deficits leading to these droughts; (3) the key catchment characteristics influencing drought propagation; and (4) the way in which drought propagation has evolved under changing climate conditions. By analyzing long-term observational records from 50 Swedish catchments, the study reveals that drought propagation is highly variable and influenced by a complex interplay of catchment characteristics, hydroclimatic conditions, and soil properties. Soil moisture exhibits the shortest propagation times, often responding within a month to precipitation deficits, while groundwater shows the longest and most variable response times, sometimes exceeding several months. The probability of precipitation deficits propagating into soil moisture droughts is highest, followed by streamflow and groundwater, with these probabilities increasing over time. Across all drought types, annual precipitation and streamflow emerge as the most influential factors governing both propagation time and probability. Although most catchments have become wetter year-round due to climate change, southern catchments are increasingly vulnerable to spring droughts (particularly soil moisture drought), driven by increasing evaporative demand. Despite these hydroclimatic shifts, no significant long-term trends in propagation times or probabilities have been observed over the past 60 years. These findings highlight the need for tailored region-specific water management strategies to address seasonal and regional variations in drought risks, particularly as climate change continues to reshape hydrological regimes.

Study region

The Godavari River basin, situated between the geographical coordinates of 73°21′ E to 83°09′ E and 16°07′ N to 22°50′ N, India

Study focus

The present study employed an extreme gradient boosting algorithm to enhance bias correction and spatial downscaling of climate model data from the Coupled Model Intercomparison Project Phase 6. The methodology utilized diverse training datasets, including five plausible climate models and topographic variables such as elevation, slope, and aspect. The effectiveness of the extreme gradient boosting framework in reproducing climate data was compared with the conventional quantile delta mapping approach across the basin. Additionally, both methods were evaluated across different seasons, including monsoon, pre-monsoon, and post-monsoon.

New hydrological insights for the region

The results demonstrated that the extreme gradient boosting model outperformed the quantile delta mapping approach and significantly reduced biases in downscaled climate variables. For instance, the proposed model achieved Nash-Sutcliffe efficiency values of 0.44, 0.96, and 0.97 for precipitation, maximum temperature, and minimum temperature, respectively, whereas the conventional quantile delta mapping method yielded a comparatively less values of −0.34, 0.56, and 0.75. Additionally, uncertainty estimates using the p-factor indicated that the extreme gradient boosting model exhibited lower uncertainty in reproducing the observed spatio-temporal patterns of climate variables. Overall, the proposed framework enhances the reliability of global climate model simulations, supporting robust regional-scale hydrological modeling and climate change impact assessments.

Denna kunskapsöversikt kartlägger befintlig forskning om försörjningsberedskap för livsmedel, dricksvatten, energi och transport i relation till klimatextremer. Studien undersöker hur klimatrelaterade extremhändelser påverkar dessa försörjningssystem, vilka vetenskapliga modeller och metoder som har utvecklats och använts i tidigare studier, samt vilka behov och utmaningar som kvarstår för framtida forskning. Studien genomförs som en översiktsstudie (scoping review) baserad på en granskning av 140 vetenskapliga artiklar. Resultaten visar att samtliga undersökta sektorer är sårbara för störningar i försörjningskedjor till följd av extrema naturhändelser. Studien redogör för och exemplifierar hur dessa störningar kan uppstå och vilka konsekvenser de kan få inom de olika sektorerna. Försörjningsberedskapen utmanas särskilt av beroendekedjor, som kan finnas inom en sektor eller sträcka sig över flera sektorer. Därför finns ett stort behov av fortsatt forskning om klimatextremers kaskadeffekter som kan påverka försörjningsberedskapen. Mot bakgrund av den pågående klimatförändringen och den ökad risken för sammanlänkade kriser behövs därutöver mer forskning utifrån ett polykrisperspektiv. Översiktsstudien visar även att det finns ett behov att testa och vidareutveckla vetenskapliga modeller som är särskilt anpassade till nordiska förhållanden för att producera mer relevant data och kunskap för regionen.

This literature review maps existing research on the security of supply for the food, drinking water, energy, and transport sectors in the context of climate extremes. The study examines how climate-related extreme weather impacts these supply systems, what scientific models and methods have been developed and applied in previous research, and what challenges remain for future studies. This study is conducted as a scoping review based on an analysis of 140 scientific articles. The results show that supply chains in all examined sectors are vulnerable to disruptions directly or indirectly caused by extreme weather events. The study describes how climate extremes trigger such disruptions and outlines their potential short and longterm consequences. Existing interdependencies within and across multiple sectors pose a substantial challenge to the security of supply. Therefore, further research is needed on the cascading effects of climate extremes and their implications for preparedness for supply chain disruptions. As the climate continues to change, the risk for compound events – where two or more crises occur simultaneously or sequentially – is increasing. Addressing this risk requires additional research from a polycrisis perspective. Furthermore, the review highlights the importance of testing and further developing scientific models specifically adapted to Nordic contexts to generate more relevant data and knowledge for this region.

Integrated approaches for managing natural resources are said to meet increasing demand for water, energy, and food, while maintaining the integrity of ecosystems, and ensuring equitable access to resources. The Water-Energy-Food (WEF) Nexus has been proposed as a cross-sectoral approach to manage trade-offs and exploit synergies that arise among these sectors. Although not initially included as a component of the Nexus, the role of nature in sustaining the water, energy, and food sectors and in regulating their interrelationships is increasingly recognised by Nexus researchers and practitioners. To converge existing approaches that integrate nature into the WEF Nexus and suggest a common framework, we – an interdisciplinary group of natural resources management researchers and systems thinkers from the European research network NEXUSNET COST Action – followed a collaborative process of knowledge creation combining literature review, elicitation of expert opinion and collaborative writing. Our results reveal a multiplicity of concepts utilised in the literature to represent, partially or fully, “nature” in the Nexus, such as “environment”, “ecosystems”, “ecosystem services”, “social-ecological systems”, and “biodiversity”. Disparity was also found in the role attributed to nature, represented by three key paradigms: (1) ecosystems as the fourth component of an expanded Nexus, i.e., the WEF-Ecosystems (WEFE) Nexus; (2) ecosystems as a foundational layer to the Nexus; and (3) the WEF Nexus as a central component of social-ecological systems (SES). By creating a hybrid approach that brings together the benefits of the respective paradigms, we present a forward-looking WEFE Nexus conceptualisation. This paradigm expands the mutual interlinkages among water, energy and food to the entirety of SES, thus acknowledging the social-ecological processes that are affected by and affect the WEF Nexus. The results of this collaborative research effort intend to provide researchers and stakeholders with means to better understand and ultimately manage Nexus issues towards a transformative change.

Nature-based Solutions (NbS) are increasingly promoted as responses to interconnected climate, biodiversity, and societal challenges. This report explores what NbS are, clarifies where conceptual confusion arises, and outlines their benefits and limitations, focusing on decision-making, knowledge and justice. The themes in the report were shaped at a workshop held in May 2025 with a newly established NbS network.  

The NbS network, supported by UUniCORN catalyst funding, is investigating how the use of NbS might help mitigate conflicts related to biodiversity protection and natural resource use. Its vision is to develop new research collaborations within UU that contribute to healthy, resilient, and biodiverse landscapes while also meeting diverse societal needs. Insights from network members are featured throughout the report. 

There is a global call for proactive drought risk management, stressing the need to further our understanding of the systemic nature of drought risk. Proactive drought risk management requires an understanding of not only the drought hazard itself, but also the underlying vulnerabilities in sociohydrological systems. As a result, drought vulnerability assessments are increasingly being conducted across the globe. However, drought vulnerability is complex and shaped by the social, ecological, and hydroclimatic context. Thus, understanding how vulnerability is manifested depending on regional, sectoral, or societal differences is crucial. Therefore, here we present an assessment of the practical relevance and relative impact of various drought vulnerability factors for water-dependent sectors and societies in forested cold climates. The analysis was based on the results of an online survey conducted in Sweden, targeting stakeholders from seven water-dependent sectors, working in authorities, private and public enterprises, NGOs, and trade associations. Respondents were asked to rate a comprehensive list of vulnerability factors, connected to sectoral and societal vulnerability as well as governance, based on their perceived impact on drought risk in their sector as well as for society as a whole. Results showed that the relevance and impact of individual vulnerability factors differed across sectors, with the forestry sector especially standing out compared to other sectors. Furthermore, the results indicate regional differences in societal vulnerability factors. The substantial list of vulnerability factors found to be relevant by the respondents demonstrates the complex nature of drought risk, as well as the importance of using caution when selecting generic vulnerability factors for applied vulnerability assessments. Furthermore, the results provide a comprehensive guide to both sectoral and societal drought vulnerability in sociohydrological systems located in forested cold climates.

To better understand the increasing human impact on the water cycle and the feedbacks between hydrology and society, the International Association of Hydrological Sciences (IAHS) organized the scientific decade “Panta Rhei – Everything Flows: Change in hydrology and society” (2013–2022). A key finding is the need to use integrated approaches to assess the co-evolution of human–water systems in order to avoid unintended consequences of human interventions over long periods of time. Additionally, substantial progress has been made in leveraging new data sources on human behaviour, e.g. through text mining of social media posts. Much has been learned about detecting hydrological changes and attributing them to their drivers, e.g. quantifying climate effects on floods. To achieve further progress, we recommend broadening the understanding, the discipline and training activities, while at the same time pursuing synthesis by focusing on key themes, developing innovative approaches and finding sustainable solutions to the world’s water problems.

Low-carbon transitions are essential but contested, particularly regarding what constitutes a ‘just transition’. To grasp their political nature, adopting a spatial perspective becomes indispensable, as different actors hold different views on how to allocate burdens and benefits across scales. In this study, we examine how notions of ‘justice’ are expressed and manifested spatially, negotiated between conflicting parties, and undergo changes, delving into the conflict surrounding an electric vehicle (EV) factory near Berlin, Germany. To do so, we leverage the theoretical lens of ‘hydrosocial territories’. This framework helps to understand how beliefs about desirable societal development (‘imaginaries’) interlink with actors’ perceptions of just distribution of water-related benefits and burdens, as well as decision-making power across spatial scales. We identify one territory supporting the factory and two counter-territories challenging its legitimacy. Actors of one counter-territory question the net benefit for in situ communities due to water challenges, while the other casts doubt on the legitimacy of the capitalist systems as such and considers the EV technology and its supply chains exemplary of exploitative relations in the water sector. We derive three key insights for the conceptualisation of ‘justice’: Firstly, divergence in the underlying values of desired societal development and the spatial scales at which transitions are conceptualised can affect the possibilities for compromise. Secondly, justice, as viewed by actors negotiating transitions, requires continuous reassessment due to its fluid nature. Thirdly, localities where low-carbon transitions occur are perceived at multiple spatial scales simultaneously, adding complexity to how actors understand justice. Our research holds value for the study of low-carbon transitions, illuminating the complexity, spatiality, and fluidity of justice and offering a heuristic device to capture it.

The European continent has experienced several large-scale drought events in recent years, and climate projections suggest an increasing drought risk in many parts of the world. As droughts can have large impacts on socio-hydrological systems, analyzing drought risk is an important part of proactive drought risk management and disaster risk reduction. Drought risk can be expressed as a product of hazard, exposure, and vulnerability, where vulnerability is highly contextual and complex. As droughts can affect all parts of the hydrological system, from precipitation and soil moisture to groundwater and surface water reservoirs, drought vulnerability differs depending on what part of the system is studied. Building on previous results from a survey analyzing drought vulnerability across seven water-dependent sectors, this paper explores how vulnerability factors vary based on sectors' dependency on blue water (surface and subsurface freshwater) or green water (soil moisture) in mid- and high-latitude regions. The findings reveal that drought vulnerability differs based on water type dependency, especially concerning water supply and species characteristics. Perceptions of vulnerability factors vary in number, category, and overall ranking, highlighting the importance of considering water dependency when choosing vulnerability factors for drought risk assessments and to clearly define the drought hazard types involved.